


Fate / Eternal Fog

by Eskiwen



Series: Fate Week 2021 [3]
Category: Fate/Grand Order
Genre: 'Eski are you ever going to write about other people', Fate Week 2021, Fate Week 2021: Grail, Gen, HGW AU setting, Now featuring: no formatting bullshit!! oh my god!!, the answer? fuck no
Language: English
Status: Completed
Published: 2021-01-21
Updated: 2021-01-21
Packaged: 2021-03-18 21:09:12
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,204
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28873620
Author URL: https://archiveofourown.org/users/Eskiwen/pseuds/Eskiwen
Summary: Written for Fate Week 2021, Day 3: Grail.November 1892, London. A Holy Grail War is beginning, and brings tidings of intense upheaval in London's carefully ordered criminal element.In an attempt to throw the war into chaos, a certain man tries his hand at summoning a servant - and gets someone unexpected.
Series: Fate Week 2021 [3]
Series URL: https://archiveofourown.org/series/2104092
Kudos: 9





	Fate / Eternal Fog

James Moriarty had done enough snooping around Mages and their ilk to know what the peculiar bruise on the back of his hand was, and why it had suddenly shown up one day out of nowhere.

It was almost pretty, in a way - a stylized representation of a butterfly, the wings and body making three distinct parts. Though it looked like a deep bruise on one of the more sensitive parts of the body, rubbing it produced no pain - and if he remembered correctly, letting time pass by would make it vanish as if it never appeared.

Because, by then, the Grail War would be on - the 7 masters and their Servants, all fighting to the death for the chance of a wish granted by some supposedly blessed cup.

_Preposterous._

For one, the Grail didn't just choose mages to partake - it cast it's net around a wide area, having the faint marks of what would be a Command Seal show up on even the most normal, uneducated people around. If it had only been mages, Moriarty would have lightly grumbled to himself - but told his empire to be careful of the streets at night for about a week before resuming normal activities. If the Clocktower wished to slay itself, he would happily stay out of it and merely say that it wasn't _his_ problem.

However, it _had_ become his problem the moment the mark appeared - because if it had appeared on his skin, then it could appear on _anyone_. 

And if that someone happened to be unsatisfied with his rule and decide to use their Servant to 'clean house?' 

There was a lot Moriarty could plan and account for - However, even _he_ could not hope to defeat a Servant with just wits and cunning. 

More than just that - the whole concept was absurd. Should any one man even have that kind of power at their fingertips, assuming the whole thing about it being a wish granting cup wasn't just esoteric drivel? He could trust himself and perhaps one other man with that, but in truth, he didn't desire a wish or the Grail in the slightest.

In fact, seeing the hubbub around it would most likely be...amusing. Even if he would have to doublecheck the proper ritual and gain a little more information to refresh his memory.

"So then," he mused, idly tracing a wing of the bruise with a finger, "it seems I must join in on this farce, and disrupt their little ritual."

An evil smirk crossed his face, letting himself be lost in imagination. He saw the desperation and despair on the faces of the mages participating in this war, horrified when he won and rebuked the Grail entirely - snatching away their own chances and hopes in one fell swoop. 

_Splendid._

\---

Practitioners of Magecraft would have you believe that creating a proper summoning circle was something no amateur could make - or, at least, that an amateur would make something incapable of summoning something like a Servant. 

Moriarty held no such beliefs. In fact, there was only one thing he was thinking as he finished the circle, which looked functionally crisp and perfect as any longtime mage could make it. 

_I've ruined a perfectly good floor with this nonsense._

This was merely a safe house in the slums, of course - but it pained him all the same. He'd have to find an appropriate rug to cover it later.

With a sigh, he straightened up - and dimmed the gas lights in the room. If he were to summon a long-dead hero, then the atmosphere should be _appropriately_ dramatic for it. 

What was it that it took? Ah. Mana, will...and the invitation he already bore on his hand. No Catalyst - he would make do with whatever spirit answered his call.

Taking in a breath, he began.

" _Your body shall serve under me.  
My fate shall be with your sword.  
Submit to the beckoning of the Holy Grail.  
If you submit to this will and this reason, then answer."_

The circle suddenly flared to life, red light lighting up the lines and casting a sickly glow about the room. A good sign, clearly.

Of course, Moriarty had no idea that another potential Master was also summoning their Servant elsewhere in London - the final Master, at the exact same time, down to the very tick of the seconds going by. His small detour into doublechecking to make sure that he did it by the book is what caused this impossible situation - one that would end up eventually changing the outcome of the war itself.

" _An oath shall be sworn here._  
I shall attain all virtues of all of Heaven,  
I shall have dominion over all evils of all of Hell."

He could _feel_ it - the circle was akin to casting a line out into the waters of the 'Throne' where Heroic Servants were stored, baiting the hook with a promise of having the chance to have their wish fulfilled. 

It was....not unlike a few Cons he'd pulled before.

As he spoke the last words, so too did the last Master - who was only a *breath* quicker.

So the Grail - though it did not think in a sentient fashion in the slightest - considered the situation. 

All 7 connections were made. Saber, Archer, Lancer, Rider, Caster, Assassin, And Berserker. And if the man attempting to summon had been a line or so late, then the connection could have been easily severed, and the War could commence.

But, it was only the barest of micro-seconds that separated them. The Request had already been made, and the Connection established. More than that, it was an incredibly powerful connection, rife with the ties of destiny and fate that would most likely cause a catastrophic effect on the Grail if it terminated the request of the 8th Master. 

Decision: Reached. Initializing solution.

In retrospect, it was a good thing that the one being summoned had no desire for the grail itself, and also possessed an ability that could overturn Mystery if used incorrectly. 

" _From the Seventh Heaven, attended to by three great words of power -"_

And that there was something....faintly wrong with this war. Enough to merit the summoning of the Extra Class meant to oversee such things.

Connection: Ruler established. Beginning spiritron possession-link...

" - _come forth from the ring of restraint, Protector of the Balance!"_

The circle flared so brightly he could barely see for a moment, as the sense of _something_ attempted to literally pour itself inside of him, to make it's flesh it's own and wear him like a damned _suit_ \- 

' ' **_NO!_** ' '

Were there two voices of protest being lifted? His, and another's?

Link: Rejected. Reverting to Servant / Master bond....

The something bounced off of him and landed (though he had no idea how he knew that) onto the floor nearby, feet and legs appearing out of thin air. Long legs, then a slender torso, until finally a full human was before him. 

And his eyes went wide. 

Through the odd overcoat (that looked like an unsupervised child had gotten ahold of some scissors and then hastily repaired once someone discovered the tot's handwork) the metal corset, and that frankly _unfair_ youthfulness...it was easy to see who he had summoned.

Grayish-green eyes blinked back at Moriarty in confusion, before _Sherlock Holmes_ ' mouth set itself into a thin, uncomfortable line. 

For a moment, there was silence.

Until the floodgates broke and Moriarty doubled over with the sheer force of his laughter, hands clapping as if in applause for this most incredible turn of events. 

And how could it not be? Sherlock Holmes - the man who was annoyingly nosing about in his business - was the very Servant he'd summoned to his side in this war, odd moment aside. 

To his credit, Holmes merely let Moriarty laugh, his expression going from clear disapproval to annoyed acceptance as his Master let the wave of mirth work itself out. There was only a faint wince as the Command Seals of the Ruler class settled onto his back, and the knowledge that the Grail held of the time period slipped into his mind - not that he needed it, given he was _alive_ during this time.

Once the deluge of laughter had lessened, the detective quirked up an eyebrow.

"Are you quite done?" He asked dryly.

Moriarty held up a gloved hand - wiping at his eyes to clear them of tears, a few last chuckles escaping him as he calmed down. "Ahaha, aaah...Hmhm, f-forgive me. I was merely - struck by the irony of it all. To think...the very detective that is doggedly messing about in my business would become so grand as to become a Servant himself! To think that the Grail could pull forwards as well as backwards...Hahaha, Wahaha -!"

There was another burst of (frankly quite villainous) laughter before the old spider managed to master himself once more. "Hmph, mph...Hn. So - it appears we are stuck together for the duration of this _sham_ of a War, does it not? As such, I do believe I should be allowed to hear your...what was it again? _Class?"_

Holmes nodded, speaking in a thin, terse voice - the lines of tension in his body making clear how displeased he was at being the Servant of the man he'd spent so long cornering in life. If the knowledge the Grail provided was correct, then his living self was still collecting information and data about the very man in front of him. "You're quite informed on the workings of the Grail War to discern that much, James Moriarty. My class....Is Ruler."

"I have my ways to gain information, of course. And," Moriarty said, ever so casually pulling off a glove to show the Command Seals on his hand to the detective, "Having the proof of the right to become a Master made the Church more willing to divulge information than normal."

At the unfortunate confirmation that Moriarty truly was his Master, Holmes only barely managed to keep himself from groaning. 

"Still," his Master continued, looking up at him with a quizzical expression, "I don't believe I've heard of the Ruler Class before. 7 classes, yes." Lifting his hands, a finger went up with each named class. "Saber, Archer, Lancer, Caster, Rider, Asssassin, and Berserker. Those are meant to be the classes of the summoned Servant, one to each., is it not? And yet, you claim you're something outside of those 7 containers."

"Normally, you're correct - It would only be those 7. However, outside of those lie Extra Classes, which can only be summoned under certain circumstances." Taking a moment to steeple his hands in front of him, Holmes locked gazes with his nemesis. "The Ruler class is normally summoned to judge the outcomes of the war, and make certain it keeps on it's proper course...of course, we are also expected to deal with anything that would circumvent that, such as a potential threat to the Grail, or the summoning of a Servant that would violate certain 'Laws' set in place."

"So you've become a nanny of sorts," Moriarty jeered. 

"Call it what you'd like."

Still, it did give him somewhat to think on. Was his desire to overturn the war itself and shun the grail's gift enough to call down a Ruler? Or, perhaps, were there other agents of Chaos among the Masters of the Grail war, ready to turn London into a hellscape of mythic proportions? 

It was still much too early to speculate - so he set it aside for the time being. "Well, beyond your being a minder of this bloody feud - I assume the feeling of being _invaded_ is a common thing when one summons such a lofty class?"

Holmes left his hands fall out of position, raising a hand as if cupping something - and in the blink of an eye, a large pipe was suddenly there. "In normal circumstances, when a Ruler is called - someone that is the most compatible with them in body type, personality, and demeanor will be chosen in order to merge with them, and essentially become as one."

There was a pause, in which both men quietly shuddered. 

"...And that was an outcome neither of us wanted, of course. I suspect there was an ... _error_ with the Grail, when you attempted to summon a Servant - seeing as I am alive during this time, I should have been able to 'possess' myself, in a way." 

"Instead, you nearly took _me_ over," Moriarty fumed. "And the thought of such a thing is enough to make me break out in hives! But....Hm. I hadn't expected one of my goals to be completed so early."

"One of your goals?"

With a wide smile, Moriarty spread his arms with all the drama of an actor upon the stage. "Is it not obvious? I have become the Master of the Arbiter of the War, something that should normally never occur! With this, I have already sent the balance of this war towards destruction itself! Wahahahaha!"

"A wonder you turned to crime instead of a troupe," Holmes muttered on his breath. 

"Hm? Is that the muttering of a bitter curmudgeon I hear?" 

"Oh, no. I was merely admiring your talents. A shame they'll waste away unseen, however."

With a pleasant laugh, Moriarty put on a smile that would charm lesser willed men - containing the faint gleam of a razor's edge within it. "Ah, yes - I'd almost forgotten your famously sharp tongue, Holmes. But, that does remind me that there is something I must do before we set out."

A cold jolt of foreboding lanced into the detective's gut - and was quickly confirmed as the criminal mastermind suddenly raised his hand in front of him, the Command Seals flaring to life.

"By the power of my command seal! _"_

**_Bastard!_ **

**_"_** Sherlock Holmes, I command you to _obey my orders_ no matter what they may be!"

The pull, the compulsion to give in tugged at the Servant even as he cursed his own idiocy. Of _course_ Moriarty would attempt to gain control over him using the methods he had available to him - it was practically a tantalizing reward for having accomplished a summoning that should have _never happened._

He would not allow this - even though it would tip his hand to the capabilities of the Ruler class, if was better than the alternative. 

One of the Command Seals etched on his back flared and faded as Holmes pushed back with glowing eyes against the command, causing the Seal to rebound on the one that had cast it against him. 

A yelp of pain and the smell of singed flesh accompanied the lessening of the pull to obey, and with speed far surpassing a mortal man's - he summoned his cane and thrust it as if in a riposte towards the man who was currently clutching his hand.

"No, I do not believe I will," he said coldly, the end of his cane aimed squarely at the middle of Moriarty's throat. "And for your own health, I would strongly advise against any more attempts of that kind."

There was a moment of silence, before his Master slumped his shoulders and gave a sheepish smile. "Ha. Well, I can hardly be blamed for trying, hm?"

The cane didn't move.

"...Very well. I acknowledge your advice, and promise to consider it carefully. Will that do?"

It wasn't an apology, of course - or even a vow to never do it again. But from this man....for now, it was enough to get Holmes to relax his posture, though he kept the cane at his side. "Yes, for the moment."

"Good." The sheepish smile deepened into something that seemed almost genuine, as Moriarty nodded in response. "How interesting - so Rulers have their own Command Seals, it seems. Though I assume you'd not be willing to tell me just how many you possess."

"You assume correctly."

"I suppose I will just have to compel you to listen to me the normal way, then."

"I wish you luck in that matter."

"Please, you needn't lie to my face. You have no intention of listening to me...how very unfortunate! Still, I'll let you keep your secrets - ah, no." Moriarty paused, lifting a single finger in the air. " One more question, if you will permit it. Rulers watch over the war itself, yes? Does that mean you have no desire for the grail - that you are, effectively, out of the running for it?"

Out of all the questions...that one actually took Holmes a little by surprise. "The Grail is interesting, yes - but as a focal point for the circumstances around it. I hold no desire for the wish it could grant. It's a trait all Rulers share, thus why most of them tend to be Saints."

Moriarty's smile suddenly took a wry edge. "....How interesting. Another common thread between us."

"Pardon?"

"I also have no desire for the Grail."

Of all he things he could have heard, that was something Holmes would have _never_ predicted. " _What?_ "

"Is it truly so surprising? I had always meant to throw this War into chaos itself, and watch as the mages had their dreams squandered." Straightening up, Moriarty inclined his head to the side. "An aberration of a Master, with no wish he would see granted....Along with an aberration of a Ruler who was improperly summoned. And who knows? There may yet be other rulebreakers here for you to find and punish with aplomb, other criminals in the eyes of society and perhaps even god."

Giving a quick bow, he smirked at his Servant. "At the very least, it should be entertaining to watch! And isn't that enough? Wahahahaha!"

Another tense silence stretched out between them - before Holmes closed his eyes, letting out an extremely tired sigh. "I feel as if I will come to regret this...but you may be right."

"Of course I'm right! What kind of fool do you take me for? - Ah, no, don't answer that."

"Are you certain?" Despite himself, that sphinx-like smile crossed the detective's expression. "I could easily provide you an itemized list."

"A list I'll hardly listen to! Hmph - we don't have time to keep bantering like fools." With a shake of his head, Moriarty began to stalk towards the nearest door. "Leaving here is the best course of action - We'll have to go to another home I have in wait, in order to stay a few steps ahead."

"Ahead? From - ah, I see. The Church?"

"Of course the Church! I hardly want them sticking their noses into our business, but they'll do such a thing eventually. I would rather meet them in a more secure location...."

\---

London settled in for what seemed like a normal, if chilly November night. Fog hung on the streets, as it always did - causing the streets and alleyways of the town to become hazy and indistinct, where some sort of supernatural encounter seemed almost natural and expected.

On those streets, two men moved towards another building - unaware of the story that was about to unfold around them, on the eve of the Holy Grail War's beginning.

A War that threatened not just London, but the very world itself.

**Author's Note:**

> I actually do have a lil of a London Grail War planned. SOMEDAY I'LL WRITE IT.....after I write that Umineko piece and finish Lose Your Way. 
> 
> 'Hey Eski how is there a Grail War in London,' I hear you say. I haven't figured that part out yet okay, I am a sham.


End file.
